Flat self-opening closure for composite packagings or for container nozzles or bottle necks to be closed by film material

A flat self-opening closure for a container, comprising:

• a pouring nozzle fixable on a container to be sealed with sheeting;
• a rotary cap having a cap lid and cylinder wall segments arranged concentrically to a rotating axis of said rotary cap at an inner side of said cap lid;
• and,
• a self-opening tube within said pouring nozzle able to be rotated via said rotary cap, said self-opening tube having, at a lower edge, combined piercing and cutting elements and further including nail-shaped projections at an inner side of said self-opening tube, said nail-shaped projections each having a nail shaft and a nail head extending toward a central point of said self-opening tube, each said nail shaft and a lower side of each said nail head being guides for said cylinder wall segments having a bevel running at an acute angle to a lower side of said cap lid to which a thrusting edge, vertical to said lower side of said cap lid, connects, so that when said rotary cap is rotated, said bevel acts on a respective said nail shaft of a respective said nail-shaped projection at an inner wall of said self-opening tube.